Railroad ties (a.k.a. railway ties, crossties, or railway sleepers) are elongated beams typically having uniform and trapezoidal cross-sections used to support railroad tracks. Railroad ties (RRTs) are generally laid perpendicular to the rails to hold the rails upright, to transfer loads to the track ballast and subgrade, and to keep the rails spaced to the correct gauge. A RRT is normally reinforced with steel bars, which are embedded into a RRT to improve its mechanical properties and durability. A RRT generally employs a fastening system for secure attachment with the railroad tracks.
Most RRTs manufactured today are made from conventional concrete. For the most part, existing concrete RRTs are operative and reliable for the intended purposes. Concrete RRTs, however, are not optimal in terms of both economics and environmental impact. Existing production technologies involve large energy consumption and carbon dioxide emission, leading to with unfavorable carbon footprints.
Thus, there is an on-going need for novel materials and production methods for RRTs that meet or exceed the physical and performance characteristics of conventional concrete RRTs while at the same time can be mass-produced at low cost with improved energy consumption and less environmental impact.